Almost 200 Ethiopian health workers have arrived in West Africa to bolster the response to Ebola, a disease that has ravaged weak health care systems and killed more than 300 medical staff.

The African Union (AU) said in a tweet that the Ethiopian government sent a total of 187 personnel to the region without giving a breakdown of how many would go to which countries.

The campaign, getting to zero before Christmas, continues. We are still having between five to 10 cases per day in Liberia, and that is huge.

Tolbert Nyenswah, assistant health minister

The doctors and nurses will join an AU mission against the worst Ebola outbreak on record, which has killed more than 6,800 people in Liberia, Sierra Leone and Guinea.

They will join more than 175 Nigerian medics deployed to Liberia and Sierra Leone earlier this month.

Ebola has torn through some of West Africa's weakest health systems, killing nearly 350 medical personnel.

This month, two doctors died of Ebola in Sierra Leone on the same day, bringing to 10 the number of doctors killed in by the virus in one of the worst-affected countries.

Other countries have also sent medical staff to West Africa, notably Cuba, which has sent 256 staff, with 165 in Sierra Leone and the rest in Guinea and Liberia.

"The aim of the AU is to support the government on the progress so far made. We want to expand on it, to make sure that the community also supports it," Major-General Julius Oketta, who head's the AU Ebola mission, said upon the arrival of 87 of the Ethiopian health workers to Liberia.

The bulk of the African Union's efforts in Liberia focus on Montserrado County, which is home to the country's capital and largest city Monrovia.

Once the country hardest hit by the disease, Liberia has seen a sharp decline in new infections, spawning optimism that the outbreak there may be coming to an end.